Compound piston hydraulic pump



Nov. 8, 1960 H. 1'. CHAPPELLE 2,959,132

COMPOUND PISTON avnmuuc PUMP Filed D90. 11. 1959 FIG. .1. 'F/G. 2.

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United States Patent 2,959,152 COMPOUND PISTON HYDRAULIC PUMP Homer T. Chappelle, 402 N. Johnson St,, Mineola, Tex. Filed Dec. 11, 1959, Ser. No. 858,929 4 Claims. c1. 103-44 This invention-relates to a novel and improved compound piston hydraulic pump. i

The primary Object of the invention is to provide a more efficient pump of the kind indicated wherein a rela-' hydraulically coupled to. a

tively small actuating piston is relatively large. fluid compressing or working piston, so that, on a powered stroke of the actuating piston a working force is exerted on the working piston which is proportionately greater than that exerted on the actuating piston.

Another object ofthe invention is the provision in a pump of the character indicated above of an open ram sleeve inwhich the actuating piston works, which is flanged to provide a head for one end of'the cylinder in which the larger piston works, a large piston which is hollow and has an open sleeve in which the ram sleeve slides, the hydraulic fluid present in the large piston and in the sleeves serving as a hydraulic ram and connecting rod between the pistons, and oppositely opening and closing valves on the cylinder for the intake and discharge of fluid by the pumps.

A further object of the invention is to provide a simple and uncomplex pump of the character indicated above which is composed of a small number of easily assembled parts.

Other important objects and advantageous features of the invention will be apparent from the following description and the accompanying drawings, wherein, for purposes of illustration only, a specific form of the invention is set forth in detail.

In the drawings:

Figure l is a central longitudinal section taken through a pump of the invention, showing the pistons retracted for a pumping stroke; and,

Figure 2 is a view like Figure 1, showing the pistons in a pumping stroke.

Referring in detail to the drawings, wherein like numerals designate like parts throughout the several views, the illustrated pump comprises a pump cylinder having a sidewall 12 having forward and rear free ends 14 and 16, respectively. The forward end of the cylinder 10 is closed by a flat head 18, secured to and in the free end 14, as by studs 20. A discharge check valve 22 traverses the head 18, at one side thereof, and an intake c heck valve 24 traverses the head 18 at the other side thereof, and discharge and intake pipes 26 and 28, respectively, are connected to the valves. While ball check valves are shown, any other suitable valves can be used, and can be located at any suitable places at the forward end of the cylinder 10.

Closing the rear end of the cylinder 10 is an annular lateral flange 30 which is secured on and in the free rear end 16 of the cylinder, as by means of studs 32. The flange 30 has a vent 33 to atmosphere and is fixed on and is preferably integral with the rear end of a cylindrical ram sleeve 32, which is substantially smaller in diameter than and is concentrically located in the cylinder 10. The ram sleeve 32 is substantially shorter than "ice ' the cylinder 10 and has a free and open forward end 34 which is spaced from the forward cylinder head 18, here shown as being substantially half the length of the cylinder 10. The ram sleeve 32 is provided with external ring grooves 36 in which compression sealing rings 38 I are seated. A small ring-equipped ram piston 40, having a rearwardly extending fixed piston rod 42, slides in the ram sleeve 32.

Slidably and closely circumposed on the ram sleeve 32 is a working piston sleeve 44, which is preferably somewhat shorter than the sealing tube 32, and has a free and open rear end 46. Fixed on and preferably integral with the forward end of the tube 44 is a lateral annular flange 48 which constitutes the rear end wall of a hollow large working piston 50.

The large piston 50 comprises a cup-shape element 52 having a flat forward end wall 54 and a rearwardly extending sidewall 56 which works against the cylinder sidewall 12, and has external ring grooves 58 in which compression sealing rings 60 are seated. The flange 48.

is secured on and in the open rear end of the cup-shapev element 52, as by means of studs 62. A filler plug64 closes a filler opening 66 in the forward end Wall 54.

The space 68 defined by the interiors of the large piston 50, the tube 44, the sealing tube 32, and the small piston 40 is substantially filled with suitable hydraulic fluid, so that, on a rearward retracting or intake stroke of the small piston 40, the fluid serves as a connecting rod between the small piston 40 and the large piston 50, and on a forward working stroke of thessm all piston 40, the fluid serves as a hydraulic force-multiplying ram, related to the differing diameters of the two pistons, for driving the large piston 50 forwardly in the cylinder 10, so as to compress fluid present in the space between the large cylinder and the forward cylinder head 18. Thus, fluid drawn into the cylinder 10, through the intake valve 24 on a retracting stroke of the small piston, is discharged through the discharge valve 26 on a forward working stroke of the small piston 40, by the forward movement imparted by the compressed hydraulic fluid in the space 68 to the large piston 59.

It is to be observed that there is no loss of ram fluid from the pump, except such as may get by the various sealing rings, and that such as may pass between the sleeves 32 and 44 into the space in the cylinder 10 between the tubes, the large piston 50, the cylinder sidewall 12, and the rear cylinder head 18, can discharge, along with air present in this space, through the vent 33.

While there has been shown and described herein a preferred form of the invention, it is to be understood that the invention is not necessarily confined thereto, and that any change or changes in the structure of and in the relative arrangements of components thereof are contemplated as being within the scope of the invention as defined by the claims appended hereto.

What is claimed is:

1. A compound hydraulic pump comprising a closed working cylinder, a working piston working in said cylinder, said working piston being hollow, an open sleeve projecting from said working piston, an open ended ram sleeve fixed to and opening through one end of the cylinder, said ram sleeve extending into and sealingly engaging said working cylinder sleeve, an actuating ram piston working in said ram sleeve, a vent in said one end of the working cylinder, a body of hydraulic fluid confined in the working piston and ram sleeve, and intake and discharge valve means communicating with the interior of the working cylinder between the working piston and a related end of the working cylinder.

2. A compound hydraulic pump comprising a pumping cylinder having first and second closed ends, vent means extending through said second end, a ram sleeve spaced: from the first cylinder end, an actuating ran? pisto'nsliding in said ramzslee-ve and'having a piston rod;

a hollow working piston working in the pumpingcylind'er between. the free end of the ram' sleeve and the first cylinder end,said.working piston having a first end and a'secondv end, a workingpiston sleeve fixed to the second: end of the'working piston and having a first end open-- ing into the working piston, said Working piston sleeve being slidably engaged on said ramisleeve and having a? second free. and open-end receiving said ram sleeve, a body of, hydraulic. fiuidconfined in the working piston and in theesleeves: by; the-ram piston, and intake and discharge-valve means on thexcylinder and communicating.;with.the interior of the. cylinder. between its first end. and the working piston,

' 3. Awcompound hydraulic pump comprising a pumping cylinder; having first and second closed ends, vent meansextending through said second end, a ram sleeve having a:free and open first-end and a second end fixed to; the second cylinder end and opening therethrough, said. ram sleeve being substantially smaller in diameter and shorter than the pumping cylinder with its first end spaced from the first cylinder end, an actuating ram piston sliding in said ram sleeve and having a piston rod, a hollow workingpiston working in the pumping cylinder between the free end of the ram sleeve and the first cylinder end,.said working piston having a first end and a secondiend, .a working piston-sleevefixed to the second end of.the working piston and having a first end open ing into-the: working-piston, said working piston sleeve being slidably engaged on saidramsleveand having a second free and open end receiving said rarnsleeve, a body of hydraulic fluid confined in the working piston and in the sleeves by the ram piston, and intake and discharge valve means on the cylinder and communicating with the interior of the cylinder between its first end and the working piston, said valve means comprising laterally spaced intake and discharge check valves open through the first end of the Working cylinder.

4. Kcompoun'd.hydraulicpump comprising a pumping cylinden having first and second closed ends, vent means extending throughsaid second" end, a ram sleevehaving a freefandropenfirst end and, a second end fixed to the second cylinder end and'opening therethrough, said ram sleeve being 'substantially smaller in diameter and shorter than the pumping cylinder with its first end spaced from the first cylinder end, an actuating ram piston sliding in said ram sleeve and having a piston rod, a: hollow working piston working in thepumping cylinder between the free end of the: ram; sleeve and the first; cylinder-rend; saidworking piston having a; first end and arseconde end, a working gpiston sleeve fixed to the second end of; the working. piston and.having'a firstend open.- ing into the-working; piston, said working piston sleeve being slidably engaged on said ram sleeve and having a'second free and'open end receiving said ram sleeve, 2. body of hydraulic fluid confined-in the working piston and in the sleeves by the ram piston, and intake and discharge valve means onthe cylinder and communicating with the interior of the cylinder between its first end and the working piston, said ram piston, said working piston, and said. ram sleevehaving external compressionsealin'g ,rings. i

i i I No references cited. 

